1. Field of the Invention
The present invention relates generally to a raised bodied vapor chamber structure, which can greatly lower the manufacturing cost.
2. Description of the Related Art
There is a trend to develop thinner and thinner electronic apparatuses nowadays. The ultra-thin electronic apparatus includes miniaturized components. The heat generated by the miniaturized components of the electronic apparatus has become a major obstacle to having better performance of the electronic apparatus and system. Even if the semiconductors forming the electronic component have been more and more miniaturized, the electronic apparatus is still required to have high performance.
The miniaturization of the semiconductors will lead to increase of thermal flux. The challenge to cooling the product due to increase of thermal flux exceeds the challenge simply caused by increase of total heat. This is because the increase of thermal flux will lead to overheating at different times with respect to different sizes and may cause malfunction or even burnout of the electronic apparatus.
In order to solve the problem of narrow heat dissipation space of the conventional technique, a vapor chamber (VC) is generally positioned on the chip as a heat sink. In order to increase the capillarity limit, capillary structures such as copper posts with sintered coatings, sintered posts and foamed posts are disposed in the vapor chamber as support structures and backflow passages. However, such structures are only applicable to the micro-vapor chamber with thinner upper and lower walls (under 1.5 mm). The above capillary structures are applied to the micro-vapor chamber as support structures. In this case, the micro-vapor chamber is supported only in the positions of the copper posts, sintered posts or foamed posts. The rest parts of the micro-vapor chamber are likely to collapse or sink. Under such circumstance, the planarity and strength of the entire micro-vapor chamber can be hardly maintained. As a result, it is impossible to thin the vapor chamber.
The working fluid of the vapor chamber is heated and evaporated in the evaporation section from a liquid phase into a vapor phase. After the vapor working fluid reaches the condensation section of the vapor chamber, the vapor working fluid is condensed from the vapor phase into the liquid phase. The liquid working fluid then flows back to the evaporation section for next circulation. The condensation section of the vapor chamber is generally a polished face or a face with sintered capillary structures. After the vapor working fluid is condensed in the condensation section into small water drops, under gravity or capillary attraction of the capillary structures, the liquid working fluid will flow back to the evaporation section. However, the conventional condensation section is a polished face so that the water drops will drop under gravity only after the water drops accumulate to a certain volume. Accordingly, the backflow efficiency is insufficient. Moreover, the backflow speed of the liquid working fluid is so slow that there is no working fluid in the evaporation section. As a result, a dry burn may take place to greatly lower the heat transfer efficiency. In order to enhance the backflow efficiency of the working fluid, it is necessary to add capillary structures to the vapor chamber. However, the capillary structures (such as sintered bodies or mesh bodies) will make it impossible to thin the vapor chamber.
A conventional thin heat exchange plate is formed with channels as capillary structures by means of etching or formed with support structures. However, the etching precision is poor and the processing time is quite long. As a result, the manufacturing cost for the thin heat exchange plate or vapor chamber can be hardly lowered.